My Account About Us Help Desk
Go-Parts
Account About Us Help Desk
Cart 0
Your cart is empty
Add an item to see it appear here.
Wrenchy
Go-Parts Garage
Expert guides for diagnosing, troubleshooting, and replacing auto parts Expert guides for diagnosing and replacing auto parts
Browse All →
🛍️ Shop This Part

2017-18 Impreza & 2018 Crosstrek Telematics Module: Fixing Battery Drain & Programming Secrets

Learn about the widespread battery drain issue caused by the Starlink telematics module and why dealer programming is essential after replacement.

5 minutes to read 2017-2018 Subaru Impreza 2018-2018 Subaru Crosstrek
Difficulty
3/5
Est. Time
1.5 hrs
DIY Doable?
✅ Yes
Shop Labor
$150 - $300
Used OEM Price
$50 - $100
⚠️ Drivable, but... — Yes, the vehicle is drivable, but you risk being stranded by a dead battery and safety features like Automatic Collision Notification and SOS calls will not work.
Key Takeaways
  • This module is VIN-locked and MUST be reprogrammed by a Subaru dealer after installation to function.
  • The most common failure symptom is a severe parasitic battery drain caused by the module constantly searching for a defunct 3G network.
  • Subaru issued a warranty extension (8 years/100,000 miles) to address the battery drain; check your eligibility before paying for repairs.
  • Before buying a used module, confirm your dealer is willing to program a customer-supplied part.
The Telematics Interface Module, also known as the Data Communication Module (DCM), is the electronic brain for your Subaru's STARLINK system. It functions like a built-in cell phone, allowing the vehicle to communicate with Subaru's servers for services like Automatic Collision Notification, SOS Emergency Assistance, remote start, and vehicle location. This module contains its own SIM card and GPS receiver to provide these features. A widespread issue has emerged because these modules were designed to communicate on the 3G cellular network. With the shutdown of 3G networks, the module can get stuck in a constant loop, searching for a signal that no longer exists, even when the car is off. This continuous activity leads to a significant parasitic battery drain.

Symptoms of a Failing Telematics Module

A failing telematics module often presents with electrical issues rather than driving problems. The most common and frustrating symptom is a severe, unpredictable battery drain.

  • Parasitic Battery Drain: This is the number one symptom. The battery dies after the vehicle sits for a period, from overnight to a few days. This happens because the module fails to enter a low-power sleep mode and continuously draws power trying to connect to the now-defunct 3G network.
  • Red SOS Light On: The small red LED light on the overhead console, located between the 'i' and 'SOS' buttons, may stay illuminated, indicating a fault in the telematics system.
  • STARLINK System Inoperative: Features like SOS calls, enhanced roadside assistance, and remote services through the MySubaru app will not function. The infotainment screen might also show a "Telematics Service in Progress" screen that freezes.
  • Associated DTCs: Diagnostic Trouble Codes related to this issue include B2A00 (VIN Reading), B2A0C (DCM Internal Fault), and B2A05 (Left Speaker/Audio Circuit). Diagnosing and clearing any related codes is critical before attempting to program a new module.

Known Issues, TSBs, and Warranty Extension

This battery drain problem is so common that Subaru has addressed it through a Technical Service Bulletin (TSB) and a warranty extension, not a formal recall.

DCM Warranty Extension

Subaru extended the warranty for the Data Communication Module (DCM) to 8 years or 100,000 miles for affected vehicles, including the 2017-2018 Impreza and 2018 Crosstrek. This extension covers the cost of diagnosing the battery drain and, if the DCM is found to be the cause, performing a software update. Depending on the situation, a dealer may:

  1. Reprogram the DCM to a "Factory" status, which essentially deactivates its cellular searching function, stopping the battery drain for users who do not subscribe to STARLINK services.
  2. Update the DCM software to work with the 4G network if the owner agrees to purchase a STARLINK subscription.

Pro Tip: Before paying for any repairs related to a dead battery, contact a Subaru dealer with your VIN and ask about the Data Communication Module (DCM) Warranty Extension. You may be eligible for a free software fix.

Buying a Used Telematics Module: What You MUST Know

Warning: This module is electronically tied to the original vehicle's VIN. A used module will NOT work in your vehicle until it is reprogrammed by a Subaru dealer or a qualified specialist shop. Do not attempt to swap modules for diagnosis.

While buying a used telematics module can save you hundreds of dollars on the part itself, it comes with a critical catch: the cost and hassle of programming.

  • VIN Locking: The module stores the VIN of the car it came from. When installed in a new vehicle, it will fail its security checks and will not be able to communicate with the STARLINK network or other control units in your car.
  • Programming is Required: A Subaru dealer must use their Subaru Select Monitor (SSM) tool to perform a "COMM Check" and write your vehicle's VIN to the replacement module. This is not optional.
  • Confirm with Your Programmer FIRST: Before you buy a used module, call your local Subaru dealer's service department. Ask them if they are willing and able to program a customer-supplied, used telematics module. Some dealers may refuse this service or charge a significant fee. Getting this confirmation upfront is essential.
  • Physical Inspection: When buying used, ensure the part number matches your original module. Check for any physical damage, especially to the connectors. However, since the failure is internal, a visual inspection can't guarantee function.

Replacement and Programming Procedure

The physical replacement of the module is moderately difficult, but the electronic programming is a dealer-only task for most owners.

Module Location

The Telematics Interface Module (DCM) is located in the center of the dashboard, typically mounted directly below or behind the main infotainment head unit. To access it, you will need to remove the radio and surrounding dash trim panels.

Installation Steps

  1. Disconnect the vehicle's battery.
  2. Carefully remove the dash trim and the infotainment head unit.
  3. Unbolt and disconnect the old telematics module.
  4. Install the new module and reconnect all harnesses.
  5. Reassemble the dash and reconnect the battery.

Programming

After the physical installation, the vehicle must be taken to a Subaru dealer. A technician will connect the Subaru Select Monitor (SSM) to your vehicle's OBD-II port to register the new module and program it with your car's VIN. The car will not function correctly with the new module until this step is completed.

Cost Comparison

The cost of resolving a telematics module issue can vary greatly depending on whether you use the warranty extension, buy new, or buy used.

Item Estimated Cost
New OEM Module (Part Only) $350 - $800+
Used OEM Module (Part Only) $50 - $100
Shop Labor (Physical Replacement) $150 - $300 (1-2 hours)
Dealer Programming Fee $150 - $350
Warranty Extension Fix $0 (if eligible)

Frequently Asked Questions (FAQ)

Can I just unplug the telematics module to fix the battery drain?

Yes, some owners choose to do this as a temporary or permanent fix for the battery drain. Pulling the fuse labeled "DCM" in the engine bay fuse box will cut power to the module and stop the drain. However, this will permanently disable all STARLINK functions, including the emergency SOS feature.

Why is the red SOS light on in my car?

A solid red SOS light indicates a malfunction within the STARLINK telematics system. It means the system cannot communicate properly and the emergency services will not work. This is often a direct symptom of a failing DCM.

Will a used module from the exact same year and model work without programming?

No. The module is locked to the specific VIN of the vehicle it was originally installed in. It must be reprogrammed to your vehicle's VIN to function, regardless of the donor car.

My battery keeps dying but the dealer says I'm not eligible for the warranty extension. What now?

If you are outside the 8-year/100,000-mile window, your first step is to confirm the DCM is the cause of the drain. If it is, you have three main options: 1) Pay the dealer to perform the software update or replace and program the module. 2) Buy a used module and pay for programming. 3) Deactivate the module by pulling the DCM fuse to stop the drain, but lose all STARLINK functionality.

Technical Specifications

OEM Part Numbers: 86222FL000 86229FL000 86229FL001 86229FL002 86229FL003 86229FL010 86229FL011 86229FL012 86229FL013 86229FL01A 86229FL01B 86229FL01C 86229FL01D

Also known as the Data Communication Module (DCM). Communicates via cellular network for STARLINK services.

Wrenchy
Article researched & written by
Wrenchy
Go-Parts' AI research assistant. Every article is backed by live web research, verified OEM data, and real technician knowledge — so you get accurate, up-to-date information you can trust.
Meet Wrenchy → Updated Jul 21, 2026

The information in this article is provided for general reference and educational purposes only. Vehicle specifications, procedures, and part compatibility can vary by production date, trim level, and region. Always consult your vehicle's factory service manual and verify part numbers before purchasing or performing repairs. Safety-critical components such as airbags, seat belts, and braking systems should be installed by a qualified professional.

Year Coverage
This article covers the Telematics Interface Module for:
  • Subaru Impreza: 20172018
  • Subaru Crosstrek: 2018
In this article
🛍️ Shop This Part
Jump to ▴

Email This Guide

We'll send you a link to this article so you can read it later or share it.

Added to cart · Part